:root {
  --bg: #0f172a;
  --bg-soft: #1e293b;
  --card: #ffffff;
  --ink: #0f172a;
  --muted: #64748b;
  --brand: #4f46e5;
  --brand-2: #7c3aed;
  --ok: #16a34a;
  --bad: #dc2626;
  --ring: rgba(79, 70, 229, 0.35);
  --shadow: 0 12px 40px rgba(2, 6, 23, 0.18);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  min-height: 100vh;
  background:
    radial-gradient(1200px 600px at 10% -10%, #312e81 0%, transparent 55%),
    radial-gradient(1000px 500px at 110% 10%, #6d28d9 0%, transparent 50%),
    var(--bg);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 24px 16px 48px;
}

.wrap { width: 100%; max-width: 720px; }

.brandbar {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #e2e8f0;
  margin-bottom: 18px;
}
.brandbar .logo {
  width: 40px; height: 40px; border-radius: 12px;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  display: grid; place-items: center; font-size: 22px;
  box-shadow: var(--shadow);
}
.brandbar h1 { font-size: 18px; margin: 0; font-weight: 800; letter-spacing: .2px; }
.brandbar p { margin: 0; font-size: 12.5px; color: #94a3b8; }

.card {
  background: var(--card);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: 22px;
  animation: rise .25s ease;
}
@keyframes rise { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

h2 { margin: 0 0 4px; font-size: 22px; }
.sub { color: var(--muted); margin: 0 0 18px; font-size: 14px; }

/* Menu */
.papers { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.paper {
  text-align: left;
  border: 1px solid #e5e7eb;
  background: #fff;
  border-radius: 14px;
  padding: 16px;
  cursor: pointer;
  transition: transform .15s, border-color .15s, box-shadow .15s;
}
.paper:hover { transform: translateY(-2px); border-color: var(--brand); box-shadow: 0 8px 20px var(--ring); }
.paper .pn { font-weight: 800; font-size: 17px; }
.paper .meta { color: var(--muted); font-size: 12.5px; margin-top: 4px; }
.paper .best { margin-top: 8px; font-size: 12px; color: var(--ok); font-weight: 700; }

/* Quiz header */
.qtop { display: flex; justify-content: space-between; align-items: center; font-size: 13.5px; color: var(--muted); margin-bottom: 10px; }
.qtop b { color: var(--ink); }
.timer.warn { color: var(--bad); font-weight: 800; }
.progress { height: 8px; background: #eef2f7; border-radius: 999px; overflow: hidden; margin-bottom: 18px; }
.progress > span { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--brand), var(--brand-2)); transition: width .3s; }

.qtext { font-size: 19px; font-weight: 700; line-height: 1.35; margin-bottom: 14px; }
.qimg { display: block; max-width: 260px; width: 100%; margin: 0 0 16px; border-radius: 12px; border: 1px solid #eef2f7; }

.answers { display: grid; gap: 10px; }
.answer {
  text-align: left;
  border: 2px solid #e5e7eb;
  background: #fff;
  border-radius: 12px;
  padding: 13px 14px;
  font-size: 15.5px;
  cursor: pointer;
  display: flex; gap: 10px; align-items: center;
  transition: border-color .15s, background .15s, transform .1s;
}
.answer .key {
  flex: none; width: 24px; height: 24px; border-radius: 7px;
  background: #f1f5f9; color: var(--muted); font-weight: 800; font-size: 13px;
  display: grid; place-items: center;
}
.answer:hover:not(:disabled) { border-color: var(--brand); background: #f7f7ff; }
.answer:disabled { cursor: default; }
.answer.correct { border-color: var(--ok); background: #ecfdf3; }
.answer.correct .key { background: var(--ok); color: #fff; }
.answer.incorrect { border-color: var(--bad); background: #fef2f2; }
.answer.incorrect .key { background: var(--bad); color: #fff; }

.row { display: flex; gap: 10px; margin-top: 18px; flex-wrap: wrap; }
.btn {
  border: none; border-radius: 12px; padding: 12px 20px; font-size: 15px; font-weight: 700;
  cursor: pointer; color: #fff; background: linear-gradient(135deg, var(--brand), var(--brand-2));
  box-shadow: 0 8px 20px var(--ring); transition: transform .1s, opacity .15s;
}
.btn:hover { transform: translateY(-1px); }
.btn.ghost { background: #f1f5f9; color: var(--ink); box-shadow: none; }
.btn:disabled { opacity: .5; cursor: not-allowed; transform: none; }

/* Results */
.scorehero { text-align: center; padding: 8px 0 4px; }
.scorehero .big { font-size: 48px; font-weight: 900; line-height: 1; }
.scorehero .pct { color: var(--muted); margin-top: 6px; }
.badge { display: inline-block; margin-top: 12px; padding: 6px 16px; border-radius: 999px; font-weight: 800; font-size: 14px; }
.badge.pass { background: #ecfdf3; color: var(--ok); }
.badge.fail { background: #fef2f2; color: var(--bad); }

.review { margin-top: 20px; display: grid; gap: 10px; }
.review h3 { font-size: 15px; margin: 6px 0; color: var(--muted); }
.rev {
  border: 1px solid #eef2f7; border-radius: 12px; padding: 12px 14px; font-size: 14px;
}
.rev .q { font-weight: 700; margin-bottom: 6px; }
.rev .line { display: flex; gap: 8px; }
.rev .tag { font-weight: 800; font-size: 12px; }
.rev .yours.wrong { color: var(--bad); }
.rev .yours.right { color: var(--ok); }
.rev .ans { color: var(--ok); }

.hint { text-align: center; color: #94a3b8; font-size: 12px; margin-top: 14px; }

@media (max-width: 520px) {
  .papers { grid-template-columns: 1fr; }
  .qtext { font-size: 17px; }
}